Distillation of petroleum.



NITE TATES rFIcE.

JOHN T. DAVIS, OF SAN FRANCISCO, CALIFORNIA.

DISTILLATION OF PETROLEUM.

SPECIFICATION forming part of Letters Patent NO. 671,078, dated April 2,1901.

Application filed July 19, 1899. Serial No. 724,412. (No specimens) Toall whom it may concern.-

Be it known that I, JOHN T. DAVIS, a citizen of the United States,residing at San Francisco, in the county of San Francisco and State ofCalifornia, have invented certain new and useful Improvements inDistillation of Petroleu m, of which the following is a specification.

In Letters Patent of the United States granted March 14, 1899, andnumbered 621,041 I describe a binding composition to unite suitablesubstance into a mass and increase the inflammability of a resultingfuel. That binding composition is made of asphaltum, crude petroleum,and bituminous coal. The asphaltum there employed is describedas being either manufactured asphaltum, by which is meant the hardresiduum from the distillation of crude petroleum, or-natural asphaltum.The crude petroleum was used with the a'sphaltum to soften and toughenit and increase its elasticity and tenacity, it having been found thatwithout this the manufactured asphaltu n1 was lacking in toughness andtenacity, so that briquets of fuel made with it would in a short timefall to pieces or, if burned, crumble as soon as exposed to heat.

The object of the present invention is to produce a binder which willhave the requisite toughness, tenacity, and stability without theaddition of petroleum.

By the ordinary methods in which different distillates are produced atgradually-increasing temperatures and in which residuums of differentconsistencies or degrees of hardness result no residuum, so far as I amaware, has been produced which alone is suitable for my purpose. Thereason for this is that the various distillates are drawn off from thestill when the temperature reaches a given point, and thereafter thetemperature is increased to make a second or a third or a fourthdistillate, the residuum of each of which has a different degree ofconsistency or hardness. In the fractional distillation of petroleum Ihave found many surprising results, some of which, as in point, aregiven, as follows: The heavier hydrocarbon vapors that leave the body ofthe residuum in the still at temperatures ranging from 550 to 600Fahrenheit or more do not pass off freely, but appear to recondense andfall back into the residuum, preventing desirable hardening of the same.

To get rid of this particular series of the hydrocarbons, air or gas hasbeen blown or drawn through the still to act as a vehicle for carryingthem off. In my efforts the temperature of the still was increased to apoint at which the portion in contact with the heated iron began tocarbonize; but this greatly impaired the value of the product for mypurpose. The difiiculty was finally dvercome simply by a prolonged orcontinuous distillation, keeping the temperature just below the initialpoint of carbonization, which I found to be about 660 Fahrenheit, andcontinuing the distillation at about such temperature until the residuumreached the requisite consistency. The result was the production of anasphalt-i0 product of a hardness, toughness, elasticity, and tenacitythat just suits the purpose of agglomerating coal-dust into anartificial fuel, this then remaining unchanged in any climate and underany condition. To effect my purpose, then, the distillation of crudepetroleum must be at a temperature that will obviate carbonizing effectand will yet produce a residuum of proper consistency.

In practice I find that it is necessary to raise the temperature to apdkeep at a point approximating, but below,the carbonizing-point of theresiduum, which is about 660 Fahrenheit, and generally this will be atleast over 640 Fahrenheit. My chief procedure, therefore, consists indistilling the hydrocarbon substance after .driving off the lighterhydrocarbons between the tempertures of 600 and 660 Fahrenheit, somewhatmore or less, and continuing the distillation at a temperature below 660Fahrenheit until the desired consistency is attained, all without blastor draft of air through the still, and thus by what may be termed simpleor plain distillation. The proper consistency and condition of theproduct are ascertained by taking a sample from time to time from thestill and dropping it into cold water, so that it can be examined at thenormal temperature of the atmosphere. When the sample is found to be ofthe hardness, toughness, &c., desired, the distillation is at oncestopped and the finished product removed from the still. In this formthe product can be substituted for the asphaltu m and crude petroleum asspecified in the patent of March 14:, 1899, No.

621,041. While the temperature of the still will also pass from thenormal to 600 Fahrenheit, as ordinarily, yet such temperatures aremerely incidental to the present procedure,where the maxim um limit is apoint just below carbonization.

In cases where the crude petroleum is of suclfa character as to containan excessive or unusal amount of the heavier hydrocarbonssuch, forinstance, as paraflinand which require high temperatures in distillationto carry them off I find it desirable to introduce a suitable oxidizingagent, such as bichromate of potash, in proper proportions, the effectof which is to hold back, solidify, and toughen these hydrocarbons,which thus become part of the asphaltic series the toughness of which isincreased, and this I accomplish by adding to each ton of crudepetroleum from two to five pounds of bi'chromate of potash, finelypulverized and thoroughly incorporated with the crude petroleum beforebeing introduced in the still, and during the process of distillati6nintroducing steam in a fine spray at the bottom of the petroleum, sothat this steam in passing up through the mass will dissolve thebichromate and permit it to act upon the petroleum while it is beingdistilled, the same conditions of temperature below thecarbonizing-point being observed during the process of distillation asis maintained when the oxidizing agent is not used. In the process ofdistillation the steam is not introduced into the still until thelighter hydrocarbons have passed off. The same effect can be produced byinjecting into the still during the process of distillation bichromateof potash, in the same proportions as before, previously dissolved inhot water, preferably in a saturated solution.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent of the United States, is

1. The process of producing a residuum suitable for use in abinder forartificial fuel,

which consists in distilling crude petroleum to a temperatureapproximating to, bntbelow, 660 Fahrenheit, and continuing thedistillation at such temperature until the residuum has reached therequired condition, substantially as described.

2. The process of producing a residuum suitable for use as a binder forartificial fuel, which consists in distilling crude petroleum in thepresence of an oxidizing agent, and to a temperature approximating to,out below, 660 Fahrenheit, and continuing the distillation at suchtemperature, until the residuum has reached the condition desired,substantially as set forth.

3. The process of producing a residuum suitable for use in a binder forartificial fuel, which consists in distilling crude petroleum in thepresence of bichromate of potash, and to a temperature above 600Fahrenheit, but below the carbonizing-point of the residuum, andcontinuing the distillation at such temperature, until the residuum hasreached the condition desired, substantially as specified.

4:. The process of producing a residuum for use as a binder forartificial fuel, which consists in incorporating with crude petroleum asuitable oxidizing agent, such as bichromate of potash, then distillingthe petroleu m to a temperature above 600 Fahrenheit, but below thecarbonizing-point of the residuum, introducing steam into the petroleumfrom below, in its passagedipward to dissolve the oxidizing agent, andcontinuing the distillation at the temperature given, until the residuumhas reached the condition desired, all substantially as set forth.

In testimony whereof I have aifixed my sig nature, in presence of twowitnesses, this 10th day of July, 1899.

JNO. T. DAVIS.

Witnesses:

L. W. SEELY, FANNY BURT.

